The graphics are very funny. The main character is adorable, and I love how comically huge the sword is in comparison. Intro cutscene is great, too. I would have like a bit more feedback when hitting / being hit (flashing, knockback, etc), but I love the extra touch of keeping the robot body parts around until you exit the level.
The combat is definitely hard. Spinning and parrying timing is really tricky, but satisfying when you line everything up correctly. I wish the camera was a little bit more zoomed out (or let me zoom in/out) so that I could get a better sense of upcoming enemies; as it stand now, I have to react pretty quickly to them. I also feel like if the robots took away a little bit less health, that might remove some of the concerns about difficulty (there's a mean feedback loop where getting hurt makes the game harder by limiting your spin).
Sfx and music are solid, but the music loop is short enough that it gets a little repetitive over the course of a run.
All-in-all, I had a lot of fun with this. I definitely struggled with the combat (and have not beaten the boss yet), but it was a good kind of challenge. Nice work!